2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved.
3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved.
5 * This code is derived from software contributed to The DragonFly Project
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
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15 * documentation and/or other materials provided with the distribution.
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17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
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21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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66 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
67 * $FreeBSD: src/sys/netinet/ip_input.c,v 1.130.2.52 2003/03/07 07:01:28 silby Exp $
68 * $DragonFly: src/sys/netinet/ip_input.c,v 1.111 2008/10/21 13:51:01 sephe Exp $
73 #include "opt_bootp.h"
76 #include "opt_ipdivert.h"
77 #include "opt_ipfilter.h"
78 #include "opt_ipstealth.h"
79 #include "opt_ipsec.h"
81 #include <sys/param.h>
82 #include <sys/systm.h>
84 #include <sys/malloc.h>
85 #include <sys/mpipe.h>
86 #include <sys/domain.h>
87 #include <sys/protosw.h>
88 #include <sys/socket.h>
90 #include <sys/globaldata.h>
91 #include <sys/thread.h>
92 #include <sys/kernel.h>
93 #include <sys/syslog.h>
94 #include <sys/sysctl.h>
95 #include <sys/in_cksum.h>
98 #include <machine/stdarg.h>
101 #include <net/if_types.h>
102 #include <net/if_var.h>
103 #include <net/if_dl.h>
104 #include <net/pfil.h>
105 #include <net/route.h>
106 #include <net/netisr.h>
108 #include <netinet/in.h>
109 #include <netinet/in_systm.h>
110 #include <netinet/in_var.h>
111 #include <netinet/ip.h>
112 #include <netinet/in_pcb.h>
113 #include <netinet/ip_var.h>
114 #include <netinet/ip_icmp.h>
115 #include <netinet/ip_divert.h>
117 #include <sys/thread2.h>
118 #include <sys/msgport2.h>
119 #include <net/netmsg2.h>
121 #include <sys/socketvar.h>
123 #include <net/ipfw/ip_fw.h>
124 #include <net/dummynet/ip_dummynet.h>
127 #include <netinet6/ipsec.h>
128 #include <netproto/key/key.h>
132 #include <netproto/ipsec/ipsec.h>
133 #include <netproto/ipsec/key.h>
137 static int ip_rsvp_on
;
138 struct socket
*ip_rsvpd
;
141 TUNABLE_INT("net.inet.ip.mpsafe", &ip_mpsafe
);
143 int ipforwarding
= 0;
144 SYSCTL_INT(_net_inet_ip
, IPCTL_FORWARDING
, forwarding
, CTLFLAG_RW
,
145 &ipforwarding
, 0, "Enable IP forwarding between interfaces");
147 static int ipsendredirects
= 1; /* XXX */
148 SYSCTL_INT(_net_inet_ip
, IPCTL_SENDREDIRECTS
, redirect
, CTLFLAG_RW
,
149 &ipsendredirects
, 0, "Enable sending IP redirects");
151 int ip_defttl
= IPDEFTTL
;
152 SYSCTL_INT(_net_inet_ip
, IPCTL_DEFTTL
, ttl
, CTLFLAG_RW
,
153 &ip_defttl
, 0, "Maximum TTL on IP packets");
155 static int ip_dosourceroute
= 0;
156 SYSCTL_INT(_net_inet_ip
, IPCTL_SOURCEROUTE
, sourceroute
, CTLFLAG_RW
,
157 &ip_dosourceroute
, 0, "Enable forwarding source routed IP packets");
159 static int ip_acceptsourceroute
= 0;
160 SYSCTL_INT(_net_inet_ip
, IPCTL_ACCEPTSOURCEROUTE
, accept_sourceroute
,
161 CTLFLAG_RW
, &ip_acceptsourceroute
, 0,
162 "Enable accepting source routed IP packets");
164 static int ip_keepfaith
= 0;
165 SYSCTL_INT(_net_inet_ip
, IPCTL_KEEPFAITH
, keepfaith
, CTLFLAG_RW
,
167 "Enable packet capture for FAITH IPv4->IPv6 translator daemon");
169 static int nipq
= 0; /* total # of reass queues */
171 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, maxfragpackets
, CTLFLAG_RW
,
173 "Maximum number of IPv4 fragment reassembly queue entries");
175 static int maxfragsperpacket
;
176 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, maxfragsperpacket
, CTLFLAG_RW
,
177 &maxfragsperpacket
, 0,
178 "Maximum number of IPv4 fragments allowed per packet");
180 static int ip_sendsourcequench
= 0;
181 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, sendsourcequench
, CTLFLAG_RW
,
182 &ip_sendsourcequench
, 0,
183 "Enable the transmission of source quench packets");
185 int ip_do_randomid
= 1;
186 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, random_id
, CTLFLAG_RW
,
188 "Assign random ip_id values");
190 * XXX - Setting ip_checkinterface mostly implements the receive side of
191 * the Strong ES model described in RFC 1122, but since the routing table
192 * and transmit implementation do not implement the Strong ES model,
193 * setting this to 1 results in an odd hybrid.
195 * XXX - ip_checkinterface currently must be disabled if you use ipnat
196 * to translate the destination address to another local interface.
198 * XXX - ip_checkinterface must be disabled if you add IP aliases
199 * to the loopback interface instead of the interface where the
200 * packets for those addresses are received.
202 static int ip_checkinterface
= 0;
203 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, check_interface
, CTLFLAG_RW
,
204 &ip_checkinterface
, 0, "Verify packet arrives on correct interface");
207 static int ipprintfs
= 0;
210 extern int udp_mpsafe_proto
;
211 extern int tcp_mpsafe_proto
;
213 extern struct domain inetdomain
;
214 extern struct protosw inetsw
[];
215 u_char ip_protox
[IPPROTO_MAX
];
216 struct in_ifaddrhead in_ifaddrheads
[MAXCPU
]; /* first inet address */
217 struct in_ifaddrhashhead
*in_ifaddrhashtbls
[MAXCPU
];
218 /* inet addr hash table */
219 u_long in_ifaddrhmask
; /* mask for hash table */
221 struct ip_stats ipstats_percpu
[MAXCPU
];
224 sysctl_ipstats(SYSCTL_HANDLER_ARGS
)
228 for (cpu
= 0; cpu
< ncpus
; ++cpu
) {
229 if ((error
= SYSCTL_OUT(req
, &ipstats_percpu
[cpu
],
230 sizeof(struct ip_stats
))))
232 if ((error
= SYSCTL_IN(req
, &ipstats_percpu
[cpu
],
233 sizeof(struct ip_stats
))))
239 SYSCTL_PROC(_net_inet_ip
, IPCTL_STATS
, stats
, (CTLTYPE_OPAQUE
| CTLFLAG_RW
),
240 0, 0, sysctl_ipstats
, "S,ip_stats", "IP statistics");
242 SYSCTL_STRUCT(_net_inet_ip
, IPCTL_STATS
, stats
, CTLFLAG_RW
,
243 &ipstat
, ip_stats
, "IP statistics");
246 /* Packet reassembly stuff */
247 #define IPREASS_NHASH_LOG2 6
248 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
249 #define IPREASS_HMASK (IPREASS_NHASH - 1)
250 #define IPREASS_HASH(x,y) \
251 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
253 static struct ipq ipq
[IPREASS_NHASH
];
256 SYSCTL_INT(_net_inet_ip
, IPCTL_DEFMTU
, mtu
, CTLFLAG_RW
,
257 &ip_mtu
, 0, "Default MTU");
261 static int ipstealth
= 0;
262 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, stealth
, CTLFLAG_RW
, &ipstealth
, 0, "");
264 static const int ipstealth
= 0;
267 struct mbuf
*(*ip_divert_p
)(struct mbuf
*, int, int);
269 struct pfil_head inet_pfil_hook
;
272 * struct ip_srcrt_opt is used to store packet state while it travels
275 * XXX Note that the code even makes assumptions on the size and
276 * alignment of fields inside struct ip_srcrt so e.g. adding some
277 * fields will break the code. This needs to be fixed.
279 * We need to save the IP options in case a protocol wants to respond
280 * to an incoming packet over the same route if the packet got here
281 * using IP source routing. This allows connection establishment and
282 * maintenance when the remote end is on a network that is not known
286 struct in_addr dst
; /* final destination */
287 char nop
; /* one NOP to align */
288 char srcopt
[IPOPT_OFFSET
+ 1]; /* OPTVAL, OLEN and OFFSET */
289 struct in_addr route
[MAX_IPOPTLEN
/sizeof(struct in_addr
)];
292 struct ip_srcrt_opt
{
294 struct ip_srcrt ip_srcrt
;
297 static MALLOC_DEFINE(M_IPQ
, "ipq", "IP Fragment Management");
298 static struct malloc_pipe ipq_mpipe
;
300 static void save_rte(struct mbuf
*, u_char
*, struct in_addr
);
301 static int ip_dooptions(struct mbuf
*m
, int, struct sockaddr_in
*);
302 static void ip_freef(struct ipq
*);
303 static void ip_input_handler(struct netmsg
*);
306 * IP initialization: fill in IP protocol switch table.
307 * All protocols not implemented in kernel go to raw IP protocol handler.
320 * Make sure we can handle a reasonable number of fragments but
321 * cap it at 4000 (XXX).
323 mpipe_init(&ipq_mpipe
, M_IPQ
, sizeof(struct ipq
),
324 IFQ_MAXLEN
, 4000, 0, NULL
);
325 for (i
= 0; i
< ncpus
; ++i
) {
326 TAILQ_INIT(&in_ifaddrheads
[i
]);
327 in_ifaddrhashtbls
[i
] =
328 hashinit(INADDR_NHASH
, M_IFADDR
, &in_ifaddrhmask
);
330 pr
= pffindproto(PF_INET
, IPPROTO_RAW
, SOCK_RAW
);
333 for (i
= 0; i
< IPPROTO_MAX
; i
++)
334 ip_protox
[i
] = pr
- inetsw
;
335 for (pr
= inetdomain
.dom_protosw
;
336 pr
< inetdomain
.dom_protoswNPROTOSW
; pr
++) {
337 if (pr
->pr_domain
->dom_family
== PF_INET
&& pr
->pr_protocol
) {
338 if (pr
->pr_protocol
!= IPPROTO_RAW
)
339 ip_protox
[pr
->pr_protocol
] = pr
- inetsw
;
342 switch (pr
->pr_protocol
) {
344 if (tcp_mpsafe_proto
)
345 pr
->pr_flags
|= PR_MPSAFE
;
349 if (udp_mpsafe_proto
)
350 pr
->pr_flags
|= PR_MPSAFE
;
356 inet_pfil_hook
.ph_type
= PFIL_TYPE_AF
;
357 inet_pfil_hook
.ph_af
= AF_INET
;
358 if ((i
= pfil_head_register(&inet_pfil_hook
)) != 0) {
359 kprintf("%s: WARNING: unable to register pfil hook, "
360 "error %d\n", __func__
, i
);
363 for (i
= 0; i
< IPREASS_NHASH
; i
++)
364 ipq
[i
].next
= ipq
[i
].prev
= &ipq
[i
];
366 maxnipq
= nmbclusters
/ 32;
367 maxfragsperpacket
= 16;
369 ip_id
= time_second
& 0xffff;
372 * Initialize IP statistics counters for each CPU.
376 for (cpu
= 0; cpu
< ncpus
; ++cpu
) {
377 bzero(&ipstats_percpu
[cpu
], sizeof(struct ip_stats
));
380 bzero(&ipstat
, sizeof(struct ip_stats
));
383 #if defined(IPSEC) || defined(FAST_IPSEC)
384 /* XXX IPSEC is not MPSAFE yet */
385 flags
= NETISR_FLAG_NOTMPSAFE
;
388 kprintf("ip: MPSAFE\n");
389 flags
= NETISR_FLAG_MPSAFE
;
391 flags
= NETISR_FLAG_NOTMPSAFE
;
394 netisr_register(NETISR_IP
, ip_mport_in
, ip_input_handler
, flags
);
398 * XXX watch out this one. It is perhaps used as a cache for
399 * the most recently used route ? it is cleared in in_addroute()
400 * when a new route is successfully created.
402 struct route ipforward_rt
[MAXCPU
];
404 /* Do transport protocol processing. */
406 transport_processing_oncpu(struct mbuf
*m
, int hlen
, struct ip
*ip
)
408 const struct protosw
*pr
= &inetsw
[ip_protox
[ip
->ip_p
]];
411 * Switch out to protocol's input routine.
414 pr
->pr_input(m
, hlen
, ip
->ip_p
);
419 transport_processing_handler(netmsg_t netmsg
)
421 struct netmsg_packet
*pmsg
= (struct netmsg_packet
*)netmsg
;
425 ip
= mtod(pmsg
->nm_packet
, struct ip
*);
426 hlen
= pmsg
->nm_netmsg
.nm_lmsg
.u
.ms_result
;
428 transport_processing_oncpu(pmsg
->nm_packet
, hlen
, ip
);
429 /* netmsg was embedded in the mbuf, do not reply! */
433 ip_input_handler(struct netmsg
*msg0
)
435 struct mbuf
*m
= ((struct netmsg_packet
*)msg0
)->nm_packet
;
438 /* msg0 was embedded in the mbuf, do not reply! */
442 * IP input routine. Checksum and byte swap header. If fragmented
443 * try to reassemble. Process options. Pass to next level.
446 ip_input(struct mbuf
*m
)
449 struct in_ifaddr
*ia
= NULL
;
450 struct in_ifaddr_container
*iac
;
453 struct in_addr pkt_dst
;
454 boolean_t using_srcrt
= FALSE
; /* forward (by PFIL_HOOKS) */
455 boolean_t needredispatch
= FALSE
;
456 struct in_addr odst
; /* original dst address(NAT) */
458 struct sockaddr_in
*next_hop
= NULL
;
460 struct tdb_ident
*tdbi
;
461 struct secpolicy
*sp
;
467 if (m
->m_pkthdr
.fw_flags
& IPFORWARD_MBUF_TAGGED
) {
469 mtag
= m_tag_find(m
, PACKET_TAG_IPFORWARD
, NULL
);
470 KKASSERT(mtag
!= NULL
);
471 next_hop
= m_tag_data(mtag
);
474 if (m
->m_pkthdr
.fw_flags
& DUMMYNET_MBUF_TAGGED
) {
475 /* dummynet already filtered us */
476 ip
= mtod(m
, struct ip
*);
477 hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
483 /* length checks already done in ip_demux() */
484 KASSERT(m
->m_len
>= sizeof(ip
), ("IP header not in one mbuf"));
486 ip
= mtod(m
, struct ip
*);
488 if (IP_VHL_V(ip
->ip_vhl
) != IPVERSION
) {
489 ipstat
.ips_badvers
++;
493 hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
494 /* length checks already done in ip_demux() */
495 KASSERT(hlen
>= sizeof(struct ip
), ("IP header len too small"));
496 KASSERT(m
->m_len
>= hlen
, ("packet shorter than IP header length"));
498 /* 127/8 must not appear on wire - RFC1122 */
499 if ((ntohl(ip
->ip_dst
.s_addr
) >> IN_CLASSA_NSHIFT
) == IN_LOOPBACKNET
||
500 (ntohl(ip
->ip_src
.s_addr
) >> IN_CLASSA_NSHIFT
) == IN_LOOPBACKNET
) {
501 if (!(m
->m_pkthdr
.rcvif
->if_flags
& IFF_LOOPBACK
)) {
502 ipstat
.ips_badaddr
++;
507 if (m
->m_pkthdr
.csum_flags
& CSUM_IP_CHECKED
) {
508 sum
= !(m
->m_pkthdr
.csum_flags
& CSUM_IP_VALID
);
510 if (hlen
== sizeof(struct ip
)) {
511 sum
= in_cksum_hdr(ip
);
513 sum
= in_cksum(m
, hlen
);
522 if (altq_input
!= NULL
&& (*altq_input
)(m
, AF_INET
) == 0) {
523 /* packet is dropped by traffic conditioner */
528 * Convert fields to host representation.
530 ip
->ip_len
= ntohs(ip
->ip_len
);
531 if (ip
->ip_len
< hlen
) {
535 ip
->ip_off
= ntohs(ip
->ip_off
);
538 * Check that the amount of data in the buffers
539 * is as at least much as the IP header would have us expect.
540 * Trim mbufs if longer than we expect.
541 * Drop packet if shorter than we expect.
543 if (m
->m_pkthdr
.len
< ip
->ip_len
) {
544 ipstat
.ips_tooshort
++;
547 if (m
->m_pkthdr
.len
> ip
->ip_len
) {
548 if (m
->m_len
== m
->m_pkthdr
.len
) {
549 m
->m_len
= ip
->ip_len
;
550 m
->m_pkthdr
.len
= ip
->ip_len
;
552 m_adj(m
, ip
->ip_len
- m
->m_pkthdr
.len
);
554 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
556 * Bypass packet filtering for packets from a tunnel (gif).
558 if (ipsec_gethist(m
, NULL
))
564 * Right now when no processing on packet has done
565 * and it is still fresh out of network we do our black
567 * - Firewall: deny/allow/divert
568 * - Xlate: translate packet's addr/port (NAT).
569 * - Pipe: pass pkt through dummynet.
570 * - Wrap: fake packet's addr/port <unimpl.>
571 * - Encapsulate: put it in another IP and send out. <unimp.>
576 * If we've been forwarded from the output side, then
577 * skip the firewall a second time
579 if (next_hop
!= NULL
)
583 if (!pfil_has_hooks(&inet_pfil_hook
)) {
584 if (m
->m_pkthdr
.fw_flags
& DUMMYNET_MBUF_TAGGED
) {
586 * Strip dummynet tags from stranded packets
588 mtag
= m_tag_find(m
, PACKET_TAG_DUMMYNET
, NULL
);
589 KKASSERT(mtag
!= NULL
);
590 m_tag_delete(m
, mtag
);
591 m
->m_pkthdr
.fw_flags
&= ~DUMMYNET_MBUF_TAGGED
;
597 * Run through list of hooks for input packets.
599 * NB: Beware of the destination address changing (e.g.
600 * by NAT rewriting). When this happens, tell
601 * ip_forward to do the right thing.
604 if (pfil_run_hooks(&inet_pfil_hook
, &m
, m
->m_pkthdr
.rcvif
, PFIL_IN
))
606 if (m
== NULL
) /* consumed by filter */
608 ip
= mtod(m
, struct ip
*);
609 hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
610 using_srcrt
= (odst
.s_addr
!= ip
->ip_dst
.s_addr
);
612 if (m
->m_pkthdr
.fw_flags
& IPFORWARD_MBUF_TAGGED
) {
613 mtag
= m_tag_find(m
, PACKET_TAG_IPFORWARD
, NULL
);
614 KKASSERT(mtag
!= NULL
);
615 next_hop
= m_tag_data(mtag
);
617 if (m
->m_pkthdr
.fw_flags
& DUMMYNET_MBUF_TAGGED
) {
621 if (m
->m_pkthdr
.fw_flags
& FW_MBUF_REDISPATCH
) {
622 needredispatch
= TRUE
;
623 m
->m_pkthdr
.fw_flags
&= ~FW_MBUF_REDISPATCH
;
627 * Process options and, if not destined for us,
628 * ship it on. ip_dooptions returns 1 when an
629 * error was detected (causing an icmp message
630 * to be sent and the original packet to be freed).
632 if (hlen
> sizeof(struct ip
) && ip_dooptions(m
, 0, next_hop
))
635 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
636 * matter if it is destined to another node, or whether it is
637 * a multicast one, RSVP wants it! and prevents it from being forwarded
638 * anywhere else. Also checks if the rsvp daemon is running before
639 * grabbing the packet.
641 if (rsvp_on
&& ip
->ip_p
== IPPROTO_RSVP
)
645 * Check our list of addresses, to see if the packet is for us.
646 * If we don't have any addresses, assume any unicast packet
647 * we receive might be for us (and let the upper layers deal
650 if (TAILQ_EMPTY(&in_ifaddrheads
[mycpuid
]) &&
651 !(m
->m_flags
& (M_MCAST
| M_BCAST
)))
655 * Cache the destination address of the packet; this may be
656 * changed by use of 'ipfw fwd'.
658 pkt_dst
= next_hop
? next_hop
->sin_addr
: ip
->ip_dst
;
661 * Enable a consistency check between the destination address
662 * and the arrival interface for a unicast packet (the RFC 1122
663 * strong ES model) if IP forwarding is disabled and the packet
664 * is not locally generated and the packet is not subject to
667 * XXX - Checking also should be disabled if the destination
668 * address is ipnat'ed to a different interface.
670 * XXX - Checking is incompatible with IP aliases added
671 * to the loopback interface instead of the interface where
672 * the packets are received.
674 checkif
= ip_checkinterface
&&
676 m
->m_pkthdr
.rcvif
!= NULL
&&
677 !(m
->m_pkthdr
.rcvif
->if_flags
& IFF_LOOPBACK
) &&
681 * Check for exact addresses in the hash bucket.
683 LIST_FOREACH(iac
, INADDR_HASH(pkt_dst
.s_addr
), ia_hash
) {
687 * If the address matches, verify that the packet
688 * arrived via the correct interface if checking is
691 if (IA_SIN(ia
)->sin_addr
.s_addr
== pkt_dst
.s_addr
&&
692 (!checkif
|| ia
->ia_ifp
== m
->m_pkthdr
.rcvif
))
698 * Check for broadcast addresses.
700 * Only accept broadcast packets that arrive via the matching
701 * interface. Reception of forwarded directed broadcasts would
702 * be handled via ip_forward() and ether_output() with the loopback
703 * into the stack for SIMPLEX interfaces handled by ether_output().
705 if (m
->m_pkthdr
.rcvif
->if_flags
& IFF_BROADCAST
) {
706 struct ifaddr_container
*ifac
;
708 TAILQ_FOREACH(ifac
, &m
->m_pkthdr
.rcvif
->if_addrheads
[mycpuid
],
710 struct ifaddr
*ifa
= ifac
->ifa
;
712 if (ifa
->ifa_addr
== NULL
) /* shutdown/startup race */
714 if (ifa
->ifa_addr
->sa_family
!= AF_INET
)
717 if (satosin(&ia
->ia_broadaddr
)->sin_addr
.s_addr
==
720 if (ia
->ia_netbroadcast
.s_addr
== pkt_dst
.s_addr
)
723 if (IA_SIN(ia
)->sin_addr
.s_addr
== INADDR_ANY
)
728 if (IN_MULTICAST(ntohl(ip
->ip_dst
.s_addr
))) {
729 struct in_multi
*inm
;
731 /* XXX Multicast is not MPSAFE yet */
734 if (ip_mrouter
!= NULL
) {
736 * If we are acting as a multicast router, all
737 * incoming multicast packets are passed to the
738 * kernel-level multicast forwarding function.
739 * The packet is returned (relatively) intact; if
740 * ip_mforward() returns a non-zero value, the packet
741 * must be discarded, else it may be accepted below.
743 if (ip_mforward
!= NULL
&&
744 ip_mforward(ip
, m
->m_pkthdr
.rcvif
, m
, NULL
) != 0) {
746 ipstat
.ips_cantforward
++;
752 * The process-level routing daemon needs to receive
753 * all multicast IGMP packets, whether or not this
754 * host belongs to their destination groups.
756 if (ip
->ip_p
== IPPROTO_IGMP
) {
760 ipstat
.ips_forward
++;
763 * See if we belong to the destination multicast group on the
766 IN_LOOKUP_MULTI(ip
->ip_dst
, m
->m_pkthdr
.rcvif
, inm
);
769 ipstat
.ips_notmember
++;
777 if (ip
->ip_dst
.s_addr
== INADDR_BROADCAST
)
779 if (ip
->ip_dst
.s_addr
== INADDR_ANY
)
783 * FAITH(Firewall Aided Internet Translator)
785 if (m
->m_pkthdr
.rcvif
&& m
->m_pkthdr
.rcvif
->if_type
== IFT_FAITH
) {
787 if (ip
->ip_p
== IPPROTO_TCP
|| ip
->ip_p
== IPPROTO_ICMP
)
795 * Not for us; forward if possible and desirable.
798 ipstat
.ips_cantforward
++;
803 * Enforce inbound IPsec SPD.
805 if (ipsec4_in_reject(m
, NULL
)) {
806 ipsecstat
.in_polvio
++;
811 mtag
= m_tag_find(m
, PACKET_TAG_IPSEC_IN_DONE
, NULL
);
814 tdbi
= (struct tdb_ident
*)m_tag_data(mtag
);
815 sp
= ipsec_getpolicy(tdbi
, IPSEC_DIR_INBOUND
);
817 sp
= ipsec_getpolicybyaddr(m
, IPSEC_DIR_INBOUND
,
818 IP_FORWARDING
, &error
);
820 if (sp
== NULL
) { /* NB: can happen if error */
822 /*XXX error stat???*/
823 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
828 * Check security policy against packet attributes.
830 error
= ipsec_in_reject(sp
, m
);
834 ipstat
.ips_cantforward
++;
838 ip_forward(m
, using_srcrt
, next_hop
);
845 * IPSTEALTH: Process non-routing options only
846 * if the packet is destined for us.
849 hlen
> sizeof(struct ip
) &&
850 ip_dooptions(m
, 1, next_hop
))
853 /* Count the packet in the ip address stats */
855 ia
->ia_ifa
.if_ipackets
++;
856 ia
->ia_ifa
.if_ibytes
+= m
->m_pkthdr
.len
;
860 * If offset or IP_MF are set, must reassemble.
861 * Otherwise, nothing need be done.
862 * (We could look in the reassembly queue to see
863 * if the packet was previously fragmented,
864 * but it's not worth the time; just let them time out.)
866 if (ip
->ip_off
& (IP_MF
| IP_OFFMASK
)) {
868 * Attempt reassembly; if it succeeds, proceed.
869 * ip_reass() will return a different mbuf.
874 ip
= mtod(m
, struct ip
*);
876 /* Get the header length of the reassembled packet */
877 hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
879 needredispatch
= TRUE
;
886 * enforce IPsec policy checking if we are seeing last header.
887 * note that we do not visit this with protocols with pcb layer
888 * code - like udp/tcp/raw ip.
890 if ((inetsw
[ip_protox
[ip
->ip_p
]].pr_flags
& PR_LASTHDR
) &&
891 ipsec4_in_reject(m
, NULL
)) {
892 ipsecstat
.in_polvio
++;
898 * enforce IPsec policy checking if we are seeing last header.
899 * note that we do not visit this with protocols with pcb layer
900 * code - like udp/tcp/raw ip.
902 if (inetsw
[ip_protox
[ip
->ip_p
]].pr_flags
& PR_LASTHDR
) {
904 * Check if the packet has already had IPsec processing
905 * done. If so, then just pass it along. This tag gets
906 * set during AH, ESP, etc. input handling, before the
907 * packet is returned to the ip input queue for delivery.
909 mtag
= m_tag_find(m
, PACKET_TAG_IPSEC_IN_DONE
, NULL
);
912 tdbi
= (struct tdb_ident
*)m_tag_data(mtag
);
913 sp
= ipsec_getpolicy(tdbi
, IPSEC_DIR_INBOUND
);
915 sp
= ipsec_getpolicybyaddr(m
, IPSEC_DIR_INBOUND
,
916 IP_FORWARDING
, &error
);
920 * Check security policy against packet attributes.
922 error
= ipsec_in_reject(sp
, m
);
925 /* XXX error stat??? */
927 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
934 #endif /* FAST_IPSEC */
936 ipstat
.ips_delivered
++;
937 if (needredispatch
) {
938 struct netmsg_packet
*pmsg
;
941 ip
->ip_off
= htons(ip
->ip_off
);
942 ip
->ip_len
= htons(ip
->ip_len
);
943 port
= ip_mport_in(&m
);
947 pmsg
= &m
->m_hdr
.mh_netmsg
;
948 netmsg_init(&pmsg
->nm_netmsg
, &netisr_apanic_rport
, MSGF_MPSAFE
,
949 transport_processing_handler
);
951 pmsg
->nm_netmsg
.nm_lmsg
.u
.ms_result
= hlen
;
953 ip
= mtod(m
, struct ip
*);
954 ip
->ip_len
= ntohs(ip
->ip_len
);
955 ip
->ip_off
= ntohs(ip
->ip_off
);
956 lwkt_sendmsg(port
, &pmsg
->nm_netmsg
.nm_lmsg
);
958 transport_processing_oncpu(m
, hlen
, ip
);
967 * Take incoming datagram fragment and try to reassemble it into
968 * whole datagram. If a chain for reassembly of this datagram already
969 * exists, then it is given as fp; otherwise have to make a chain.
972 ip_reass(struct mbuf
*m
)
974 struct ip
*ip
= mtod(m
, struct ip
*);
975 struct mbuf
*p
= NULL
, *q
, *nq
;
977 struct ipq
*fp
= NULL
;
978 int hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
982 /* If maxnipq is 0, never accept fragments. */
984 ipstat
.ips_fragments
++;
985 ipstat
.ips_fragdropped
++;
990 sum
= IPREASS_HASH(ip
->ip_src
.s_addr
, ip
->ip_id
);
992 * Look for queue of fragments of this datagram.
994 for (fp
= ipq
[sum
].next
; fp
!= &ipq
[sum
]; fp
= fp
->next
)
995 if (ip
->ip_id
== fp
->ipq_id
&&
996 ip
->ip_src
.s_addr
== fp
->ipq_src
.s_addr
&&
997 ip
->ip_dst
.s_addr
== fp
->ipq_dst
.s_addr
&&
998 ip
->ip_p
== fp
->ipq_p
)
1004 * Enforce upper bound on number of fragmented packets
1005 * for which we attempt reassembly;
1006 * If maxnipq is -1, accept all fragments without limitation.
1008 if (nipq
> maxnipq
&& maxnipq
> 0) {
1010 * drop something from the tail of the current queue
1011 * before proceeding further
1013 if (ipq
[sum
].prev
== &ipq
[sum
]) { /* gak */
1014 for (i
= 0; i
< IPREASS_NHASH
; i
++) {
1015 if (ipq
[i
].prev
!= &ipq
[i
]) {
1016 ipstat
.ips_fragtimeout
+=
1017 ipq
[i
].prev
->ipq_nfrags
;
1018 ip_freef(ipq
[i
].prev
);
1023 ipstat
.ips_fragtimeout
+=
1024 ipq
[sum
].prev
->ipq_nfrags
;
1025 ip_freef(ipq
[sum
].prev
);
1030 * Adjust ip_len to not reflect header,
1031 * convert offset of this to bytes.
1034 if (ip
->ip_off
& IP_MF
) {
1036 * Make sure that fragments have a data length
1037 * that's a non-zero multiple of 8 bytes.
1039 if (ip
->ip_len
== 0 || (ip
->ip_len
& 0x7) != 0) {
1040 ipstat
.ips_toosmall
++; /* XXX */
1044 m
->m_flags
|= M_FRAG
;
1046 m
->m_flags
&= ~M_FRAG
;
1049 ipstat
.ips_fragments
++;
1050 m
->m_pkthdr
.header
= ip
;
1053 * If the hardware has not done csum over this fragment
1054 * then csum_data is not valid at all.
1056 if ((m
->m_pkthdr
.csum_flags
& (CSUM_FRAG_NOT_CHECKED
| CSUM_DATA_VALID
))
1057 == (CSUM_FRAG_NOT_CHECKED
| CSUM_DATA_VALID
)) {
1058 m
->m_pkthdr
.csum_data
= 0;
1059 m
->m_pkthdr
.csum_flags
&= ~(CSUM_DATA_VALID
| CSUM_PSEUDO_HDR
);
1063 * Presence of header sizes in mbufs
1064 * would confuse code below.
1070 * If first fragment to arrive, create a reassembly queue.
1073 if ((fp
= mpipe_alloc_nowait(&ipq_mpipe
)) == NULL
)
1075 insque(fp
, &ipq
[sum
]);
1078 fp
->ipq_ttl
= IPFRAGTTL
;
1079 fp
->ipq_p
= ip
->ip_p
;
1080 fp
->ipq_id
= ip
->ip_id
;
1081 fp
->ipq_src
= ip
->ip_src
;
1082 fp
->ipq_dst
= ip
->ip_dst
;
1084 m
->m_nextpkt
= NULL
;
1090 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
1093 * Find a segment which begins after this one does.
1095 for (p
= NULL
, q
= fp
->ipq_frags
; q
; p
= q
, q
= q
->m_nextpkt
)
1096 if (GETIP(q
)->ip_off
> ip
->ip_off
)
1100 * If there is a preceding segment, it may provide some of
1101 * our data already. If so, drop the data from the incoming
1102 * segment. If it provides all of our data, drop us, otherwise
1103 * stick new segment in the proper place.
1105 * If some of the data is dropped from the the preceding
1106 * segment, then it's checksum is invalidated.
1109 i
= GETIP(p
)->ip_off
+ GETIP(p
)->ip_len
- ip
->ip_off
;
1111 if (i
>= ip
->ip_len
)
1114 m
->m_pkthdr
.csum_flags
= 0;
1118 m
->m_nextpkt
= p
->m_nextpkt
;
1121 m
->m_nextpkt
= fp
->ipq_frags
;
1126 * While we overlap succeeding segments trim them or,
1127 * if they are completely covered, dequeue them.
1129 for (; q
!= NULL
&& ip
->ip_off
+ ip
->ip_len
> GETIP(q
)->ip_off
;
1131 i
= (ip
->ip_off
+ ip
->ip_len
) - GETIP(q
)->ip_off
;
1132 if (i
< GETIP(q
)->ip_len
) {
1133 GETIP(q
)->ip_len
-= i
;
1134 GETIP(q
)->ip_off
+= i
;
1136 q
->m_pkthdr
.csum_flags
= 0;
1141 ipstat
.ips_fragdropped
++;
1143 q
->m_nextpkt
= NULL
;
1149 * Check for complete reassembly and perform frag per packet
1152 * Frag limiting is performed here so that the nth frag has
1153 * a chance to complete the packet before we drop the packet.
1154 * As a result, n+1 frags are actually allowed per packet, but
1155 * only n will ever be stored. (n = maxfragsperpacket.)
1159 for (p
= NULL
, q
= fp
->ipq_frags
; q
; p
= q
, q
= q
->m_nextpkt
) {
1160 if (GETIP(q
)->ip_off
!= next
) {
1161 if (fp
->ipq_nfrags
> maxfragsperpacket
) {
1162 ipstat
.ips_fragdropped
+= fp
->ipq_nfrags
;
1167 next
+= GETIP(q
)->ip_len
;
1169 /* Make sure the last packet didn't have the IP_MF flag */
1170 if (p
->m_flags
& M_FRAG
) {
1171 if (fp
->ipq_nfrags
> maxfragsperpacket
) {
1172 ipstat
.ips_fragdropped
+= fp
->ipq_nfrags
;
1179 * Reassembly is complete. Make sure the packet is a sane size.
1183 if (next
+ (IP_VHL_HL(ip
->ip_vhl
) << 2) > IP_MAXPACKET
) {
1184 ipstat
.ips_toolong
++;
1185 ipstat
.ips_fragdropped
+= fp
->ipq_nfrags
;
1191 * Concatenate fragments.
1198 q
->m_nextpkt
= NULL
;
1199 for (q
= nq
; q
!= NULL
; q
= nq
) {
1201 q
->m_nextpkt
= NULL
;
1202 m
->m_pkthdr
.csum_flags
&= q
->m_pkthdr
.csum_flags
;
1203 m
->m_pkthdr
.csum_data
+= q
->m_pkthdr
.csum_data
;
1208 * Clean up the 1's complement checksum. Carry over 16 bits must
1209 * be added back. This assumes no more then 65535 packet fragments
1210 * were reassembled. A second carry can also occur (but not a third).
1212 m
->m_pkthdr
.csum_data
= (m
->m_pkthdr
.csum_data
& 0xffff) +
1213 (m
->m_pkthdr
.csum_data
>> 16);
1214 if (m
->m_pkthdr
.csum_data
> 0xFFFF)
1215 m
->m_pkthdr
.csum_data
-= 0xFFFF;
1218 * Create header for new ip packet by
1219 * modifying header of first packet;
1220 * dequeue and discard fragment reassembly header.
1221 * Make header visible.
1224 ip
->ip_src
= fp
->ipq_src
;
1225 ip
->ip_dst
= fp
->ipq_dst
;
1228 mpipe_free(&ipq_mpipe
, fp
);
1229 m
->m_len
+= (IP_VHL_HL(ip
->ip_vhl
) << 2);
1230 m
->m_data
-= (IP_VHL_HL(ip
->ip_vhl
) << 2);
1231 /* some debugging cruft by sklower, below, will go away soon */
1232 if (m
->m_flags
& M_PKTHDR
) { /* XXX this should be done elsewhere */
1235 for (n
= m
; n
; n
= n
->m_next
)
1237 m
->m_pkthdr
.len
= plen
;
1240 ipstat
.ips_reassembled
++;
1244 ipstat
.ips_fragdropped
++;
1254 * Free a fragment reassembly header and all
1255 * associated datagrams.
1258 ip_freef(struct ipq
*fp
)
1262 while (fp
->ipq_frags
) {
1264 fp
->ipq_frags
= q
->m_nextpkt
;
1265 q
->m_nextpkt
= NULL
;
1269 mpipe_free(&ipq_mpipe
, fp
);
1274 * IP timer processing;
1275 * if a timer expires on a reassembly
1276 * queue, discard it.
1285 for (i
= 0; i
< IPREASS_NHASH
; i
++) {
1289 while (fp
!= &ipq
[i
]) {
1292 if (fp
->prev
->ipq_ttl
== 0) {
1293 ipstat
.ips_fragtimeout
+= fp
->prev
->ipq_nfrags
;
1299 * If we are over the maximum number of fragments
1300 * (due to the limit being lowered), drain off
1301 * enough to get down to the new limit.
1303 if (maxnipq
>= 0 && nipq
> maxnipq
) {
1304 for (i
= 0; i
< IPREASS_NHASH
; i
++) {
1305 while (nipq
> maxnipq
&&
1306 (ipq
[i
].next
!= &ipq
[i
])) {
1307 ipstat
.ips_fragdropped
+=
1308 ipq
[i
].next
->ipq_nfrags
;
1309 ip_freef(ipq
[i
].next
);
1318 * Drain off all datagram fragments.
1325 for (i
= 0; i
< IPREASS_NHASH
; i
++) {
1326 while (ipq
[i
].next
!= &ipq
[i
]) {
1327 ipstat
.ips_fragdropped
+= ipq
[i
].next
->ipq_nfrags
;
1328 ip_freef(ipq
[i
].next
);
1335 * Do option processing on a datagram,
1336 * possibly discarding it if bad options are encountered,
1337 * or forwarding it if source-routed.
1338 * The pass argument is used when operating in the IPSTEALTH
1339 * mode to tell what options to process:
1340 * [LS]SRR (pass 0) or the others (pass 1).
1341 * The reason for as many as two passes is that when doing IPSTEALTH,
1342 * non-routing options should be processed only if the packet is for us.
1343 * Returns 1 if packet has been forwarded/freed,
1344 * 0 if the packet should be processed further.
1347 ip_dooptions(struct mbuf
*m
, int pass
, struct sockaddr_in
*next_hop
)
1349 struct sockaddr_in ipaddr
= { sizeof ipaddr
, AF_INET
};
1350 struct ip
*ip
= mtod(m
, struct ip
*);
1352 struct in_ifaddr
*ia
;
1353 int opt
, optlen
, cnt
, off
, code
, type
= ICMP_PARAMPROB
;
1354 boolean_t forward
= FALSE
;
1355 struct in_addr
*sin
, dst
;
1359 cp
= (u_char
*)(ip
+ 1);
1360 cnt
= (IP_VHL_HL(ip
->ip_vhl
) << 2) - sizeof(struct ip
);
1361 for (; cnt
> 0; cnt
-= optlen
, cp
+= optlen
) {
1362 opt
= cp
[IPOPT_OPTVAL
];
1363 if (opt
== IPOPT_EOL
)
1365 if (opt
== IPOPT_NOP
)
1368 if (cnt
< IPOPT_OLEN
+ sizeof(*cp
)) {
1369 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1372 optlen
= cp
[IPOPT_OLEN
];
1373 if (optlen
< IPOPT_OLEN
+ sizeof(*cp
) || optlen
> cnt
) {
1374 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1384 * Source routing with record.
1385 * Find interface with current destination address.
1386 * If none on this machine then drop if strictly routed,
1387 * or do nothing if loosely routed.
1388 * Record interface address and bring up next address
1389 * component. If strictly routed make sure next
1390 * address is on directly accessible net.
1394 if (ipstealth
&& pass
> 0)
1396 if (optlen
< IPOPT_OFFSET
+ sizeof(*cp
)) {
1397 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1400 if ((off
= cp
[IPOPT_OFFSET
]) < IPOPT_MINOFF
) {
1401 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1404 ipaddr
.sin_addr
= ip
->ip_dst
;
1405 ia
= (struct in_ifaddr
*)
1406 ifa_ifwithaddr((struct sockaddr
*)&ipaddr
);
1408 if (opt
== IPOPT_SSRR
) {
1409 type
= ICMP_UNREACH
;
1410 code
= ICMP_UNREACH_SRCFAIL
;
1413 if (!ip_dosourceroute
)
1414 goto nosourcerouting
;
1416 * Loose routing, and not at next destination
1417 * yet; nothing to do except forward.
1421 off
--; /* 0 origin */
1422 if (off
> optlen
- (int)sizeof(struct in_addr
)) {
1424 * End of source route. Should be for us.
1426 if (!ip_acceptsourceroute
)
1427 goto nosourcerouting
;
1428 save_rte(m
, cp
, ip
->ip_src
);
1433 if (!ip_dosourceroute
) {
1435 char buf
[sizeof "aaa.bbb.ccc.ddd"];
1438 * Acting as a router, so generate ICMP
1441 strcpy(buf
, inet_ntoa(ip
->ip_dst
));
1443 "attempted source route from %s to %s\n",
1444 inet_ntoa(ip
->ip_src
), buf
);
1445 type
= ICMP_UNREACH
;
1446 code
= ICMP_UNREACH_SRCFAIL
;
1450 * Not acting as a router,
1454 ipstat
.ips_cantforward
++;
1461 * locate outgoing interface
1463 memcpy(&ipaddr
.sin_addr
, cp
+ off
,
1464 sizeof ipaddr
.sin_addr
);
1466 if (opt
== IPOPT_SSRR
) {
1467 #define INA struct in_ifaddr *
1468 #define SA struct sockaddr *
1469 if ((ia
= (INA
)ifa_ifwithdstaddr((SA
)&ipaddr
))
1471 ia
= (INA
)ifa_ifwithnet((SA
)&ipaddr
);
1473 ia
= ip_rtaddr(ipaddr
.sin_addr
,
1474 &ipforward_rt
[mycpuid
]);
1476 type
= ICMP_UNREACH
;
1477 code
= ICMP_UNREACH_SRCFAIL
;
1480 ip
->ip_dst
= ipaddr
.sin_addr
;
1481 memcpy(cp
+ off
, &IA_SIN(ia
)->sin_addr
,
1482 sizeof(struct in_addr
));
1483 cp
[IPOPT_OFFSET
] += sizeof(struct in_addr
);
1485 * Let ip_intr's mcast routing check handle mcast pkts
1487 forward
= !IN_MULTICAST(ntohl(ip
->ip_dst
.s_addr
));
1491 if (ipstealth
&& pass
== 0)
1493 if (optlen
< IPOPT_OFFSET
+ sizeof(*cp
)) {
1494 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1497 if ((off
= cp
[IPOPT_OFFSET
]) < IPOPT_MINOFF
) {
1498 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1502 * If no space remains, ignore.
1504 off
--; /* 0 origin */
1505 if (off
> optlen
- (int)sizeof(struct in_addr
))
1507 memcpy(&ipaddr
.sin_addr
, &ip
->ip_dst
,
1508 sizeof ipaddr
.sin_addr
);
1510 * locate outgoing interface; if we're the destination,
1511 * use the incoming interface (should be same).
1513 if ((ia
= (INA
)ifa_ifwithaddr((SA
)&ipaddr
)) == NULL
&&
1514 (ia
= ip_rtaddr(ipaddr
.sin_addr
,
1515 &ipforward_rt
[mycpuid
]))
1517 type
= ICMP_UNREACH
;
1518 code
= ICMP_UNREACH_HOST
;
1521 memcpy(cp
+ off
, &IA_SIN(ia
)->sin_addr
,
1522 sizeof(struct in_addr
));
1523 cp
[IPOPT_OFFSET
] += sizeof(struct in_addr
);
1527 if (ipstealth
&& pass
== 0)
1529 code
= cp
- (u_char
*)ip
;
1530 if (optlen
< 4 || optlen
> 40) {
1531 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1534 if ((off
= cp
[IPOPT_OFFSET
]) < 5) {
1535 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1538 if (off
> optlen
- (int)sizeof(int32_t)) {
1539 cp
[IPOPT_OFFSET
+ 1] += (1 << 4);
1540 if ((cp
[IPOPT_OFFSET
+ 1] & 0xf0) == 0) {
1541 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1546 off
--; /* 0 origin */
1547 sin
= (struct in_addr
*)(cp
+ off
);
1548 switch (cp
[IPOPT_OFFSET
+ 1] & 0x0f) {
1550 case IPOPT_TS_TSONLY
:
1553 case IPOPT_TS_TSANDADDR
:
1554 if (off
+ sizeof(n_time
) +
1555 sizeof(struct in_addr
) > optlen
) {
1556 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1559 ipaddr
.sin_addr
= dst
;
1560 ia
= (INA
)ifaof_ifpforaddr((SA
)&ipaddr
,
1564 memcpy(sin
, &IA_SIN(ia
)->sin_addr
,
1565 sizeof(struct in_addr
));
1566 cp
[IPOPT_OFFSET
] += sizeof(struct in_addr
);
1567 off
+= sizeof(struct in_addr
);
1570 case IPOPT_TS_PRESPEC
:
1571 if (off
+ sizeof(n_time
) +
1572 sizeof(struct in_addr
) > optlen
) {
1573 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1576 memcpy(&ipaddr
.sin_addr
, sin
,
1577 sizeof(struct in_addr
));
1578 if (ifa_ifwithaddr((SA
)&ipaddr
) == NULL
)
1580 cp
[IPOPT_OFFSET
] += sizeof(struct in_addr
);
1581 off
+= sizeof(struct in_addr
);
1585 code
= &cp
[IPOPT_OFFSET
+ 1] - (u_char
*)ip
;
1589 memcpy(cp
+ off
, &ntime
, sizeof(n_time
));
1590 cp
[IPOPT_OFFSET
] += sizeof(n_time
);
1593 if (forward
&& ipforwarding
) {
1594 ip_forward(m
, TRUE
, next_hop
);
1599 icmp_error(m
, type
, code
, 0, 0);
1600 ipstat
.ips_badoptions
++;
1605 * Given address of next destination (final or next hop),
1606 * return internet address info of interface to be used to get there.
1609 ip_rtaddr(struct in_addr dst
, struct route
*ro
)
1611 struct sockaddr_in
*sin
;
1613 sin
= (struct sockaddr_in
*)&ro
->ro_dst
;
1615 if (ro
->ro_rt
== NULL
|| dst
.s_addr
!= sin
->sin_addr
.s_addr
) {
1616 if (ro
->ro_rt
!= NULL
) {
1620 sin
->sin_family
= AF_INET
;
1621 sin
->sin_len
= sizeof *sin
;
1622 sin
->sin_addr
= dst
;
1623 rtalloc_ign(ro
, RTF_PRCLONING
);
1626 if (ro
->ro_rt
== NULL
)
1629 return (ifatoia(ro
->ro_rt
->rt_ifa
));
1633 * Save incoming source route for use in replies,
1634 * to be picked up later by ip_srcroute if the receiver is interested.
1637 save_rte(struct mbuf
*m
, u_char
*option
, struct in_addr dst
)
1640 struct ip_srcrt_opt
*opt
;
1643 mtag
= m_tag_get(PACKET_TAG_IPSRCRT
, sizeof(*opt
), MB_DONTWAIT
);
1646 opt
= m_tag_data(mtag
);
1648 olen
= option
[IPOPT_OLEN
];
1651 kprintf("save_rte: olen %d\n", olen
);
1653 if (olen
> sizeof(opt
->ip_srcrt
) - (1 + sizeof(dst
))) {
1657 bcopy(option
, opt
->ip_srcrt
.srcopt
, olen
);
1658 opt
->ip_nhops
= (olen
- IPOPT_OFFSET
- 1) / sizeof(struct in_addr
);
1659 opt
->ip_srcrt
.dst
= dst
;
1660 m_tag_prepend(m
, mtag
);
1664 * Retrieve incoming source route for use in replies,
1665 * in the same form used by setsockopt.
1666 * The first hop is placed before the options, will be removed later.
1669 ip_srcroute(struct mbuf
*m0
)
1671 struct in_addr
*p
, *q
;
1674 struct ip_srcrt_opt
*opt
;
1679 mtag
= m_tag_find(m0
, PACKET_TAG_IPSRCRT
, NULL
);
1682 opt
= m_tag_data(mtag
);
1684 if (opt
->ip_nhops
== 0)
1686 m
= m_get(MB_DONTWAIT
, MT_HEADER
);
1690 #define OPTSIZ (sizeof(opt->ip_srcrt.nop) + sizeof(opt->ip_srcrt.srcopt))
1692 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1693 m
->m_len
= opt
->ip_nhops
* sizeof(struct in_addr
) +
1694 sizeof(struct in_addr
) + OPTSIZ
;
1697 kprintf("ip_srcroute: nhops %d mlen %d",
1698 opt
->ip_nhops
, m
->m_len
);
1703 * First save first hop for return route
1705 p
= &opt
->ip_srcrt
.route
[opt
->ip_nhops
- 1];
1706 *(mtod(m
, struct in_addr
*)) = *p
--;
1709 kprintf(" hops %x", ntohl(mtod(m
, struct in_addr
*)->s_addr
));
1713 * Copy option fields and padding (nop) to mbuf.
1715 opt
->ip_srcrt
.nop
= IPOPT_NOP
;
1716 opt
->ip_srcrt
.srcopt
[IPOPT_OFFSET
] = IPOPT_MINOFF
;
1717 memcpy(mtod(m
, caddr_t
) + sizeof(struct in_addr
), &opt
->ip_srcrt
.nop
,
1719 q
= (struct in_addr
*)(mtod(m
, caddr_t
) +
1720 sizeof(struct in_addr
) + OPTSIZ
);
1723 * Record return path as an IP source route,
1724 * reversing the path (pointers are now aligned).
1726 while (p
>= opt
->ip_srcrt
.route
) {
1729 kprintf(" %x", ntohl(q
->s_addr
));
1734 * Last hop goes to final destination.
1736 *q
= opt
->ip_srcrt
.dst
;
1737 m_tag_delete(m0
, mtag
);
1740 kprintf(" %x\n", ntohl(q
->s_addr
));
1746 * Strip out IP options.
1749 ip_stripoptions(struct mbuf
*m
)
1752 struct ip
*ip
= mtod(m
, struct ip
*);
1756 optlen
= (IP_VHL_HL(ip
->ip_vhl
) << 2) - sizeof(struct ip
);
1757 opts
= (caddr_t
)(ip
+ 1);
1758 datalen
= m
->m_len
- (sizeof(struct ip
) + optlen
);
1759 bcopy(opts
+ optlen
, opts
, datalen
);
1761 if (m
->m_flags
& M_PKTHDR
)
1762 m
->m_pkthdr
.len
-= optlen
;
1763 ip
->ip_vhl
= IP_MAKE_VHL(IPVERSION
, sizeof(struct ip
) >> 2);
1766 u_char inetctlerrmap
[PRC_NCMDS
] = {
1768 0, EMSGSIZE
, EHOSTDOWN
, EHOSTUNREACH
,
1769 EHOSTUNREACH
, EHOSTUNREACH
, ECONNREFUSED
, ECONNREFUSED
,
1770 EMSGSIZE
, EHOSTUNREACH
, 0, 0,
1772 ENOPROTOOPT
, ECONNREFUSED
1776 * Forward a packet. If some error occurs return the sender
1777 * an icmp packet. Note we can't always generate a meaningful
1778 * icmp message because icmp doesn't have a large enough repertoire
1779 * of codes and types.
1781 * If not forwarding, just drop the packet. This could be confusing
1782 * if ipforwarding was zero but some routing protocol was advancing
1783 * us as a gateway to somewhere. However, we must let the routing
1784 * protocol deal with that.
1786 * The using_srcrt parameter indicates whether the packet is being forwarded
1787 * via a source route.
1790 ip_forward(struct mbuf
*m
, boolean_t using_srcrt
, struct sockaddr_in
*next_hop
)
1792 struct ip
*ip
= mtod(m
, struct ip
*);
1793 struct sockaddr_in
*ipforward_rtaddr
;
1795 int error
, type
= 0, code
= 0, destmtu
= 0;
1798 struct in_addr pkt_dst
;
1799 struct route
*cache_rt
= &ipforward_rt
[mycpuid
];
1803 * Cache the destination address of the packet; this may be
1804 * changed by use of 'ipfw fwd'.
1806 pkt_dst
= (next_hop
!= NULL
) ? next_hop
->sin_addr
: ip
->ip_dst
;
1810 kprintf("forward: src %x dst %x ttl %x\n",
1811 ip
->ip_src
.s_addr
, pkt_dst
.s_addr
, ip
->ip_ttl
);
1814 if (m
->m_flags
& (M_BCAST
| M_MCAST
) || !in_canforward(pkt_dst
)) {
1815 ipstat
.ips_cantforward
++;
1819 if (!ipstealth
&& ip
->ip_ttl
<= IPTTLDEC
) {
1820 icmp_error(m
, ICMP_TIMXCEED
, ICMP_TIMXCEED_INTRANS
, dest
, 0);
1824 ipforward_rtaddr
= (struct sockaddr_in
*) &cache_rt
->ro_dst
;
1825 if (cache_rt
->ro_rt
== NULL
||
1826 ipforward_rtaddr
->sin_addr
.s_addr
!= pkt_dst
.s_addr
) {
1827 if (cache_rt
->ro_rt
!= NULL
) {
1828 RTFREE(cache_rt
->ro_rt
);
1829 cache_rt
->ro_rt
= NULL
;
1831 ipforward_rtaddr
->sin_family
= AF_INET
;
1832 ipforward_rtaddr
->sin_len
= sizeof(struct sockaddr_in
);
1833 ipforward_rtaddr
->sin_addr
= pkt_dst
;
1834 rtalloc_ign(cache_rt
, RTF_PRCLONING
);
1835 if (cache_rt
->ro_rt
== NULL
) {
1836 icmp_error(m
, ICMP_UNREACH
, ICMP_UNREACH_HOST
, dest
, 0);
1840 rt
= cache_rt
->ro_rt
;
1843 * Save the IP header and at most 8 bytes of the payload,
1844 * in case we need to generate an ICMP message to the src.
1846 * XXX this can be optimized a lot by saving the data in a local
1847 * buffer on the stack (72 bytes at most), and only allocating the
1848 * mbuf if really necessary. The vast majority of the packets
1849 * are forwarded without having to send an ICMP back (either
1850 * because unnecessary, or because rate limited), so we are
1851 * really we are wasting a lot of work here.
1853 * We don't use m_copy() because it might return a reference
1854 * to a shared cluster. Both this function and ip_output()
1855 * assume exclusive access to the IP header in `m', so any
1856 * data in a cluster may change before we reach icmp_error().
1858 MGETHDR(mcopy
, MB_DONTWAIT
, m
->m_type
);
1859 if (mcopy
!= NULL
&& !m_dup_pkthdr(mcopy
, m
, MB_DONTWAIT
)) {
1861 * It's probably ok if the pkthdr dup fails (because
1862 * the deep copy of the tag chain failed), but for now
1863 * be conservative and just discard the copy since
1864 * code below may some day want the tags.
1869 if (mcopy
!= NULL
) {
1870 mcopy
->m_len
= imin((IP_VHL_HL(ip
->ip_vhl
) << 2) + 8,
1872 mcopy
->m_pkthdr
.len
= mcopy
->m_len
;
1873 m_copydata(m
, 0, mcopy
->m_len
, mtod(mcopy
, caddr_t
));
1877 ip
->ip_ttl
-= IPTTLDEC
;
1880 * If forwarding packet using same interface that it came in on,
1881 * perhaps should send a redirect to sender to shortcut a hop.
1882 * Only send redirect if source is sending directly to us,
1883 * and if packet was not source routed (or has any options).
1884 * Also, don't send redirect if forwarding using a default route
1885 * or a route modified by a redirect.
1887 if (rt
->rt_ifp
== m
->m_pkthdr
.rcvif
&&
1888 !(rt
->rt_flags
& (RTF_DYNAMIC
| RTF_MODIFIED
)) &&
1889 satosin(rt_key(rt
))->sin_addr
.s_addr
!= INADDR_ANY
&&
1890 ipsendredirects
&& !using_srcrt
&& next_hop
== NULL
) {
1891 u_long src
= ntohl(ip
->ip_src
.s_addr
);
1892 struct in_ifaddr
*rt_ifa
= (struct in_ifaddr
*)rt
->rt_ifa
;
1894 if (rt_ifa
!= NULL
&&
1895 (src
& rt_ifa
->ia_subnetmask
) == rt_ifa
->ia_subnet
) {
1896 if (rt
->rt_flags
& RTF_GATEWAY
)
1897 dest
= satosin(rt
->rt_gateway
)->sin_addr
.s_addr
;
1899 dest
= pkt_dst
.s_addr
;
1901 * Router requirements says to only send
1904 type
= ICMP_REDIRECT
;
1905 code
= ICMP_REDIRECT_HOST
;
1908 kprintf("redirect (%d) to %x\n", code
, dest
);
1913 error
= ip_output(m
, NULL
, cache_rt
, IP_FORWARDING
, NULL
, NULL
);
1915 ipstat
.ips_forward
++;
1918 ipflow_create(cache_rt
, mcopy
);
1921 return; /* most common case */
1923 ipstat
.ips_redirectsent
++;
1926 ipstat
.ips_cantforward
++;
1933 * Send ICMP message.
1938 case 0: /* forwarded, but need redirect */
1939 /* type, code set above */
1942 case ENETUNREACH
: /* shouldn't happen, checked above */
1947 type
= ICMP_UNREACH
;
1948 code
= ICMP_UNREACH_HOST
;
1952 type
= ICMP_UNREACH
;
1953 code
= ICMP_UNREACH_NEEDFRAG
;
1956 * If the packet is routed over IPsec tunnel, tell the
1957 * originator the tunnel MTU.
1958 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1961 if (cache_rt
->ro_rt
!= NULL
) {
1962 struct secpolicy
*sp
= NULL
;
1967 sp
= ipsec4_getpolicybyaddr(mcopy
,
1973 destmtu
= cache_rt
->ro_rt
->rt_ifp
->if_mtu
;
1975 /* count IPsec header size */
1976 ipsechdr
= ipsec4_hdrsiz(mcopy
,
1981 * find the correct route for outer IPv4
1982 * header, compute tunnel MTU.
1985 if (sp
->req
!= NULL
&& sp
->req
->sav
!= NULL
&&
1986 sp
->req
->sav
->sah
!= NULL
) {
1987 ro
= &sp
->req
->sav
->sah
->sa_route
;
1988 if (ro
->ro_rt
!= NULL
&&
1989 ro
->ro_rt
->rt_ifp
!= NULL
) {
1991 ro
->ro_rt
->rt_ifp
->if_mtu
;
1992 destmtu
-= ipsechdr
;
2001 * If the packet is routed over IPsec tunnel, tell the
2002 * originator the tunnel MTU.
2003 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2006 if (cache_rt
->ro_rt
!= NULL
) {
2007 struct secpolicy
*sp
= NULL
;
2012 sp
= ipsec_getpolicybyaddr(mcopy
,
2018 destmtu
= cache_rt
->ro_rt
->rt_ifp
->if_mtu
;
2020 /* count IPsec header size */
2021 ipsechdr
= ipsec4_hdrsiz(mcopy
,
2026 * find the correct route for outer IPv4
2027 * header, compute tunnel MTU.
2030 if (sp
->req
!= NULL
&&
2031 sp
->req
->sav
!= NULL
&&
2032 sp
->req
->sav
->sah
!= NULL
) {
2033 ro
= &sp
->req
->sav
->sah
->sa_route
;
2034 if (ro
->ro_rt
!= NULL
&&
2035 ro
->ro_rt
->rt_ifp
!= NULL
) {
2037 ro
->ro_rt
->rt_ifp
->if_mtu
;
2038 destmtu
-= ipsechdr
;
2045 #else /* !IPSEC && !FAST_IPSEC */
2046 if (cache_rt
->ro_rt
!= NULL
)
2047 destmtu
= cache_rt
->ro_rt
->rt_ifp
->if_mtu
;
2049 ipstat
.ips_cantfrag
++;
2054 * A router should not generate ICMP_SOURCEQUENCH as
2055 * required in RFC1812 Requirements for IP Version 4 Routers.
2056 * Source quench could be a big problem under DoS attacks,
2057 * or if the underlying interface is rate-limited.
2058 * Those who need source quench packets may re-enable them
2059 * via the net.inet.ip.sendsourcequench sysctl.
2061 if (!ip_sendsourcequench
) {
2065 type
= ICMP_SOURCEQUENCH
;
2070 case EACCES
: /* ipfw denied packet */
2074 icmp_error(mcopy
, type
, code
, dest
, destmtu
);
2078 ip_savecontrol(struct inpcb
*inp
, struct mbuf
**mp
, struct ip
*ip
,
2081 if (inp
->inp_socket
->so_options
& SO_TIMESTAMP
) {
2085 *mp
= sbcreatecontrol((caddr_t
) &tv
, sizeof(tv
),
2086 SCM_TIMESTAMP
, SOL_SOCKET
);
2088 mp
= &(*mp
)->m_next
;
2090 if (inp
->inp_flags
& INP_RECVDSTADDR
) {
2091 *mp
= sbcreatecontrol((caddr_t
) &ip
->ip_dst
,
2092 sizeof(struct in_addr
), IP_RECVDSTADDR
, IPPROTO_IP
);
2094 mp
= &(*mp
)->m_next
;
2096 if (inp
->inp_flags
& INP_RECVTTL
) {
2097 *mp
= sbcreatecontrol((caddr_t
) &ip
->ip_ttl
,
2098 sizeof(u_char
), IP_RECVTTL
, IPPROTO_IP
);
2100 mp
= &(*mp
)->m_next
;
2104 * Moving these out of udp_input() made them even more broken
2105 * than they already were.
2107 /* options were tossed already */
2108 if (inp
->inp_flags
& INP_RECVOPTS
) {
2109 *mp
= sbcreatecontrol((caddr_t
) opts_deleted_above
,
2110 sizeof(struct in_addr
), IP_RECVOPTS
, IPPROTO_IP
);
2112 mp
= &(*mp
)->m_next
;
2114 /* ip_srcroute doesn't do what we want here, need to fix */
2115 if (inp
->inp_flags
& INP_RECVRETOPTS
) {
2116 *mp
= sbcreatecontrol((caddr_t
) ip_srcroute(m
),
2117 sizeof(struct in_addr
), IP_RECVRETOPTS
, IPPROTO_IP
);
2119 mp
= &(*mp
)->m_next
;
2122 if (inp
->inp_flags
& INP_RECVIF
) {
2125 struct sockaddr_dl sdl
;
2128 struct sockaddr_dl
*sdp
;
2129 struct sockaddr_dl
*sdl2
= &sdlbuf
.sdl
;
2131 if (((ifp
= m
->m_pkthdr
.rcvif
)) &&
2132 ((ifp
->if_index
!= 0) && (ifp
->if_index
<= if_index
))) {
2133 sdp
= IF_LLSOCKADDR(ifp
);
2135 * Change our mind and don't try copy.
2137 if ((sdp
->sdl_family
!= AF_LINK
) ||
2138 (sdp
->sdl_len
> sizeof(sdlbuf
))) {
2141 bcopy(sdp
, sdl2
, sdp
->sdl_len
);
2145 offsetof(struct sockaddr_dl
, sdl_data
[0]);
2146 sdl2
->sdl_family
= AF_LINK
;
2147 sdl2
->sdl_index
= 0;
2148 sdl2
->sdl_nlen
= sdl2
->sdl_alen
= sdl2
->sdl_slen
= 0;
2150 *mp
= sbcreatecontrol((caddr_t
) sdl2
, sdl2
->sdl_len
,
2151 IP_RECVIF
, IPPROTO_IP
);
2153 mp
= &(*mp
)->m_next
;
2158 * XXX these routines are called from the upper part of the kernel.
2160 * They could also be moved to ip_mroute.c, since all the RSVP
2161 * handling is done there already.
2164 ip_rsvp_init(struct socket
*so
)
2166 if (so
->so_type
!= SOCK_RAW
||
2167 so
->so_proto
->pr_protocol
!= IPPROTO_RSVP
)
2170 if (ip_rsvpd
!= NULL
)
2175 * This may seem silly, but we need to be sure we don't over-increment
2176 * the RSVP counter, in case something slips up.
2191 * This may seem silly, but we need to be sure we don't over-decrement
2192 * the RSVP counter, in case something slips up.
2202 rsvp_input(struct mbuf
*m
, ...) /* XXX must fixup manually */
2208 off
= __va_arg(ap
, int);
2209 proto
= __va_arg(ap
, int);
2212 if (rsvp_input_p
) { /* call the real one if loaded */
2213 rsvp_input_p(m
, off
, proto
);
2217 /* Can still get packets with rsvp_on = 0 if there is a local member
2218 * of the group to which the RSVP packet is addressed. But in this
2219 * case we want to throw the packet away.
2227 if (ip_rsvpd
!= NULL
) {
2228 rip_input(m
, off
, proto
);
2231 /* Drop the packet */